Integrated circuits (IC) virtually never wear out. Failure of an IC is more often due to misuse or to a manufacturing defect. Misuses such as excessive vibration, water damage, and extreme heat are difficult for a manufacturer to control. However, manufacturing defects seen by consumers may be minimized by proper quality control. IC's often undergo extensive testing. Such testing seeks to identify defective IC's before the IC is used in a circuit board or other device. Testing should be as efficient and effective as possible.
High-speed IC testing systems have been developed which rely upon a high-speed robotic handler. The handler moves discrete IC packages into and out of an IC test socket to enable electronic tests to be performed on the IC before the IC is attached to a circuit board or other device. Hi-speed robotic handlers, come in various configurations. Many include a workpress assembly which couples IC packages to the test socket base.
A typical prior art workpress assembly is illustrated by FIG. 1 which shows a known IC handling workpress. The workpress includes a bladed element which bolts directly to a portion of the workpress. The bladed element is machined having four blades. The workpress includes a vacuum cup which extends through the bladed element between the blades. The blades function to align IC packages with a test socket base.
IC packages include multiple conductive leads. The workpress blades press the leads against the test socket base during testing. Ideally, the blades precisely and uniformly press the leads into the test socket to prevent lead damage. This ideal situation is sometimes unmet. What is desired is a workpress which is precision made and which does not damage leads during high-speed IC testing.
After extended periods of high-speed IC testing, the blades may wear. When blade wear exceeds a certain acceptable limit, the workpress assembly may fail to properly align the leads with the test socket. Worn blades may deform or break the leads. Blades which are worn beyond the acceptable limit are normally replaced before the blades damage the IC's to be tested. Blade replacement is expensive. What is desired is a way of reducing the cost of blade replacement.
The blades are often custom fabricated, having a size and shape to accommodate a particular IC package size. Custom fabricated blades are normally custom machined to desired specifications. This machining process is often performed by a specialized machine shop and is relatively expensive. Using a specialized machine shop for blade fabrication may ultimately increase product costs for consumers. What is desired is a way to eliminate the need for custom fabricated blades so that consumers may save money.
The test sockets used in many IC handling systems are commercially available. Examples of test sockets are disclosed in U.S. Pat. Nos. 5,009,608; 4,615,441; 4,758,176 and 5,387,120, the disclosures of which are incorporated herein by reference. Normally each test socket includes a test socket base and a test socket cover. The test socket cover includes a clamp which applies uniform pressure to the periphery of the packaged IC when the cover is closed. The cover of these test sockets is closed by hand.
One known method utilizes IC test socket bases for use with high-speed automated IC testing. This involves removal of the test socket top cover. The top cover is then discarded and wasted. The base is attached to the automated test system and is used for automated IC testing. What is desired is a way to recycle at least a portion of the top cover instead of discarding the top cover.